The present invention relates to novel compounds selected from 2-(3-aminoaryl)amino-4-aryl-thiazoles that selectively modulate, regulate, and/or inhibit signal transduction mediated by certain native and/or mutant tyrosine kinases implicated in a variety of human and animal diseases such as cell proliferative, metabolic, allergic, and degenerative disorders. More particularly, these compounds are potent and selective c-kit inhibitors.
Tyrosine kinases are receptor type or non-receptor type proteins, which transfer the terminal phosphate of ATP to tyrosine residues of proteins thereby activating or inactivating signal transduction pathways. These proteins are known to be involved in many cellular mechanisms, which in case of disruption, lead to disorders such as abnormal cell proliferation and migration as well as inflammation.
As of today, there are about 58 known receptor tyrosine kinases. Other tyrosine kinases are the well-known VEGF receptors (Kim et al., Nature 362, pp. 841-844, 1993), PDGF receptors, c-kit and the FLK family. These receptors can transmit signals to other tyrosine kinases including Src, Raf, Frk, Btk, Csk, Abl, Fes/Fps, Fak, Jak, Ack. etc.
Among tyrosine kinase receptors, c-kit is of special interest. Indeed, c-kit is a key receptor activating mast cells, which have proved to be directly or indirectly implicated in numerous pathologies for which the Applicant filed WO 03/004007, WO 03/004006, WO 03/003006, WO 03/003004, WO 03/002114, WO 03/002109, WO 03/002108, WO 03/002107, WO 03/002106, WO 03/002105, WO 03/039550, WO 03/035050, WO 03/035049, U.S. 60/359,652 and U.S. 60/359,651.
It was found that mast cells present in tissues of patients are implicated in or contribute to the genesis of diseases such as autoimmune diseases (rheumatoid arthritis, inflammatory bowel diseases (IBD)) allergic diseases, tumor angiogenesis, inflammatory diseases, and interstitial cystitis. In these diseases, it has been shown that mast cells participate in the destruction of tissues by releasing a cocktail of different proteases and mediators such as histamine, neutral proteases, lipid-derived mediators (prostaglandins, thromboxanes and leucotrienes), and various cytokines (IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, TNF-α, GM-CSF, MIP-1a, MIP-1b, MIP-2 and IFN-γ).
The c-kit receptor also can be constitutively activated by mutations leading to abnormal cell proliferation and development of diseases such as mastocytosis and various cancers.
For this reason, it has been proposed to target c-kit to deplete the mast cells responsible for these disorders.
The main objective underlying the present invention is therefore to find potent and selective compounds capable of inhibiting wild type and/or mutated c-kit.
Many different compounds have been described as tyrosine kinase inhibitors, for example, bis monocyclic, bicyclic or heterocyclic aryl compounds (WO 92/20642), vinylene-azaindole derivatives (WO 94/14808) and 1-cycloproppyl-4-pyridyl-quinolones (U.S. Pat. No. 5,330,992), styryl compounds (U.S. Pat. No. 5,217,999), styryl-substituted pyridyl compounds (U.S. Pat. No. 5,302,606), selenoindoles and selenides (WO 94/03427), tricyclic polyhydroxylic compounds (WO 92/21660) and benzylphosphonic acid compounds (WO 91/15495), pyrimidine derivatives (U.S. Pat. No. 5,521,184 and WO 99/03854), indolinone derivatives and pyrrole-substituted indolinones (U.S. Pat. No. 5,792,783, EP 934 931, U.S. Pat. No. 5,834,504, U.S. Pat. No. 5,883,116, U.S. Pat. No. 5,883,113, U.S. Pat. No. 5,886,020, WO 96/40116 and WO 00/38519), as well as bis monocyclic, bicyclic aryl and heteroaryl compounds (EP 584 222, U.S. Pat. No. 5,656,643 and WO 92/20642), quinazoline derivatives (EP 602 851, EP 520 722, U.S. Pat. No. 3,772,295 and U.S. Pat. No. 4,343,940) and aryl and heteroaryl quinazoline (U.S. Pat. No. 5,721,237, U.S. Pat. No. 5,714,493, U.S. Pat. No. 5,710,158 and WO 95/15758).
However, none of these compounds have been described as potent and selective inhibitors of c-kit or of the c-kit pathway.
In connection with the present invention, we have found that compounds corresponding to the 2-(3-aminoaryl)amino-4-aryl-thiazoles are potent and selective inhibitors of c-kit or c-kit pathway. These compounds are good candidates for treating diseases such as autoimmunes diseases, inflammatory diseases, cancer and mastocytosis.